Clear Filters
Clear Filters

Vectorize Matrix Formation & Multiplication

2 views (last 30 days)
How can I vectorize the following code
clear;clc
t = 1:10;
v = rand(10,3);
a = rand(10,1);
m = 6:15;
n = 6:15;
M = 1:20;
N = 1:20;
P = ones(20,20);
V = zeros(size(v))';
D = zeros(size(m))';
for i = 1:length(t)
B = [1,0,0;0,cos(a(i)),sin(a(i));0,-sin(a(i)),cos(a(i))];
V(:,i) = B*v(i,:).';
D(i,1) = interp2(M,N,P,m(i),n(i));
end
V = V.'; % (size has to be same as v)
how can I rewrite this code without using loops?

Accepted Answer

Matt J
Matt J on 17 Nov 2022
Edited: Matt J on 17 Nov 2022
N=length(t);
a=reshape(a,1,1,N);
B=zeros(3,3,N) ;
B(1,1,:)=1;
B(2:3,2:3,:)=[cos(a), sin(a); -sin(a),cos(a)];
V = pagemtimes(B,reshape(v',2,1,N));
V=reshape(V,2,[]).';
D = interp2(M,N,P,m,n);
  1 Comment
Fawad Farooq Ashraf
Fawad Farooq Ashraf on 17 Nov 2022
thank you. this works indeed
although, a minor correction may be
V = pagemtimes(B,reshape(v',3,1,N));
V=reshape(V,3,[]).';
as v has 3 columns instead of 2

Sign in to comment.

More Answers (0)

Categories

Find more on MATLAB in Help Center and File Exchange

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!